312 beads - I placed them every 4th row.
I cast on 10 sts less than in pattern as that is the width I preferred. This gave me 3 lines on which to place the beads.

The yarn is very strong - the fluffy fibres are very well bonded to the main strand and remained in situ whilst knitting.
I knitted then frogged a few rows and the yarn knitted up again fine.

The ever willing model is my sister. Luckily I had enough yarn to make one for myself too as she ran off with this one…